The present invention relates to remote controls for operating electronic devices, and more particularly to universal remote controls which can be programmed to operate one of a plurality of different types of electronic devices produced by different manufacturers.
Universal remote controls are well known devices which can be programmed by a user to operate one of a plurality of different types of electronic devices produced by different manufacturers. Universal remote controls are often used to control audio/video equipment, such as TVs, VCRs, CD players and the like. Due to their programmability, consumers frequently use universal remote controls to replace lost remote controls and/or as a single control device for controlling a number of separate audio/video components.
Prior to use, a universal remote control typically must be programmed for operation with the electronic device being controlled. Programming a universal remote control generally involves identifying and storing a reference code, or some other identification information, associated with the correct signal format into a memory circuit of the universal remote control. Once programmed, the universal remote control transmits control signals having a signal format that is appropriate for the device being controlled. The signal format is determined by characteristics which include, but are not limited to, carrier frequency, pulse width, pulse modulation and overall timing.
Several methods are available for programming a universal remote control to transmit control signals having the desired signal format. One method is to manually enter the reference code associated with the controlled device. In such a method, a list of reference codes for a variety of device models is included in the printed instruction set that accompanies the universal remote control. The user finds the reference code associated with the device to be controlled and manually enters the code numbers using a numeric keypad disposed on the universal remote control. This method can be problematic for the user because the specific reference code numbers must be known in order to program the universal remote control. Thus, the reference code list must be kept nearby and consulted whenever a new code must be entered or a particular code needs to be reentered.
Another method of programming a universal remote control is an automatic code searching and storing method. In this method, the universal remote control automatically and continuously passes through a set of signal formats by sequentially sending remote control signals based on each of the signal formats in a stored list until the user stops the signal format search sequence. The user initiates and maintains the automatic search sequence by pressing a designated set of keys. During the cycling of the signal formats, the remote control pauses between each signal format allowing the user to observe whether the controlled device reacts to a particular signal format. When the controlled device reacts to the remote control signal in the desired manner, the user knows that the correct signal format, and thus the correct reference code, has been identified and terminates the automatic search sequence. Terminating the search sequence causes the universal remote control to stop cycling through the signal formats and store the reference code, or other identifying information, associated with the most recently transmitted signal format into a memory circuit.
An example of a system that employs such a method is disclosed in EP-A-0 233 307. The disclosed system is a remote control apparatus which, in response to a first input, generates and transmits a sequence of remote control signals, each of the signals in a different format. The user observes the appliance and waits for the appliance to react in an expected manner. When the appliance reacts, the user provides a second input that causes the remote control apparatus to save the last signal format transmitted.
A disadvantage of the automatic search method is that such a method requires the user to react within a predetermined pause period. The user must react within the allotted pause period when the device reacts as expected to a remote control signal in order to stop the cycling of the signal formats and store reference code associated with the desired signal format into a memory circuit. If the user is distracted and/or reacts too slowly, the improper reference code will be stored in memory and the user must repeat the code search operation to find and store the correct reference code. It can be seen that this method becomes difficult and frustrating to use if the user is repeatedly unable to react within the allotted pause periods.
Yet another method of programming a universal remote control is a semi-automatic code search method in which the user steps through a plurality of signal formats stored in a memory portion until the desired signal format is found. In this method, the user steps through a set of signal formats stored in memory by transmitting a sequence of remote control signals, one at a time, wherein each transmitted remote control signal has a different signal format, by pressing a designated set of keys. After each remote control signal format is transmitted, the user observes whether the device reacts to the transmitted signal, i.e., power ON/OFF or channel UP/DOWN. When the device reacts to the signal in the expected manner, the user knows that the appropriate signal format has been transmitted. At this point, the user presses another set of keys to terminate the code search operation and store the reference code, or other identifying information, associated with the last transmitted signal format into a memory circuit.
A difficulty with the above-described method is that the user may be forced to step through a large number of signal formats before identifying the correct signal format because there may be a large number of signal format possibilities stored in the memory circuit. In fact, the reference codes are getting longer, moving from two digits to three and four digits, due to the longer list of formats available. It can be seen that such a difficulty can make this method tedious and time consuming. This is especially problematic if the desired signal format is stored near the end of the signal format list.
What is needed is an improved method of quickly and easily programming a universal remote control to transmit remote control signals in a desired signal format. In particular, it is desired to be able to program a universal remote control without having to refer to a printed list of reference codes and manually enter a specific reference code into the universal remote control. It is also desired to be able to program a universal remote control by cycling through a set of stored signal formats wherein the user can quickly, easily and efficiently control the rate at which the stored signal formats are transmitted and tested.
The present invention involves a universal remote control and a method for programming a universal remote control which allows a user to quickly and easily test a set of stored signal formats to identify the desired signal format and store a reference code, or other identifying information, associated with the desired signal format into a memory circuit such that subsequent remote control signals will be transmitted in the desired signal format.
The present universal remote control comprises a signal transmitter, data entry means for allowing a user to enter data and one of a plurality of code search commands, a memory circuit, and a controller. The controller generates and applies one of a plurality of sets of remote control signals to the signal transmitter in response to user entry of a first code search command. Each of the sets of remote control signals comprises a plurality of remote control signals and each of the remote control signals has a respective signal format based on a list of signal formats stored in the memory circuit. The controller also generates and applies one of the remote control signals from the most recently transmitted set of remote control signals in response to user entry of a second code search command. The controller stores an identification information associated with a most recently transmitted signal format in response to user entry of a code search exit command. Advantageously the controller generates and applies the remote control signals from the most recently transmitted set of remote control signals to the signal generator, in a first predetermined order, in response to each user entry of the second code search command, and generates and applies the remote control signals from the last transmitted set of remote control signals to the signal generator, in a second predetermined order, in response to each user entry of a third code search command.
The present invention allows a user to quickly identify a set of signal formats which includes the desired signal format by entering the first code search command, and then quickly identify the specific, desired signal format from the identified set of signal formats by entering the second and third code search commands keys.
The present invention also involves a method for programming a universal remote control comprising the steps of identifying a signal set which includes a desired signal format by transmitting a plurality of signal sets until the controlled device observably responds in an expected manner, identifying the desired signal format in the identified signal set by individually transmitting the remote control signal formats included in the identified signal set until the controlled device observably responds in an expected manner, and storing an identifying information, such as a reference code, associated with the identified signal format in a memory circuit.